Jason Reitman and Sheldon Turner won for their adaptation of Walter Kirn’s novel “Up in the Air.” Pic, released by Paramount, topped “Crazy Heart,” “Julie and Julia,” “Precious” and “Star Trek.”

“I’m honored and stunned,” Boal told the audience at the WGA West ceremonies at the Century Plaza. He singled out director Kathryn Bigelow for backing “an unpopular story about an unpopular war that has now lasted twice as long as WWII with no end in sight.”

Boal also thanked the U.S. soldiers in Iraq with whom he was embedded in 2004 to learn about bomb-defusing squads.

Turner gave thanks to his fellow members for providing inspiration to him when he was a young writer with more than a dozen unproduced scripts. “We don’t write because we want to — we write because we have to,” he said.

Reitman singled out his father Ivan Reitman, a veteran helmer and a producer on “Up in the Air,” for his encouragement during the early stages of his career. “He told me, ‘You got the goods,’?” Reitman said.

The WGA screenplay awards have been a reliable indicator for Oscar winners. Winners of original screenplay trophies have matched in 10 of the last 15 years, including Dustin Lance Black last year for “Milk.” The adapted screenplay awards have matched in 11 of the last 15 years, including Simon Beaufoy last year for “Slumdog Millionaire.”

WGA Award rules allow only screenplays penned under its jurisdiction or that of an affiliate writers guild, so a quintet of the Oscar screenplay nominees were ineligible for the WGA trophies: “Inglourious Basterds” and “Up” in the original category and “District 9,” “An Education” and “In the Loop” in adapted.

Mark Monroe won the documentary award for “The Cove,” as the dolphin slaughter docu continued to pile up trophies.

On the TV side, AMC’s “Mad Men” and NBC’s “30 Rock” repeated as winners in drama and comedy series and ABC’s “Modern Family” won the new series award.

Steve Levitan, co-creator and exec producer of “Modern Family” with Christopher Lloyd, made heartfelt mention of how many other writers have reached out to say how much they’re rooting for the domestic laffer to succeed, given the drought of successful comedies in recent years. He got a rise from the crowd by concluding, “Thanks, Jeff Zucker!”

Fox’s “House” won the drama episode award for the “Broken: Part 1 and 2″ segment penned by Russel Friend, Garrett Lerner, David Foster and David Shore; there was a tie in the comedy episode category between the “30 Rock” seg “Apollo” by Robert Carlock and the “Modern Family” pilot by Levitan and Lloyd.

Carlock, who accepted the award at the WGA East ceremony held Saturday at the Hudson Theater in New York, said: “It’s a group effort when you’re writing these things, except for this one amazing exception. So I’m glad you’re all here to witness this historic moment.”

Nickelodeon’s “Welcome to the Jungle” took the children’s episodic and specials kudo. The longform original nod went to Lifetime’s “Georgia O’Keeffe” and the longform adapted kudo to HBO’s “Taking Chance.” “Saturday Night Live” and “The Daily Show With Jon Stewart” tied in the comedy-variety category, and CBS’ “The Young and the Restless” took the daytime trophy.

Animation nod went to “The Simpsons” scribe Joel H. Cohen for the episode “Wedding for Disaster” over four other “Simpsons” segments. When the nominees were announced in New York, the presenters (all from “Sesame Street”) started to sing “One of These Things Is Not Like the Other” with five identical “Simpsons” logos arranged on the screen.

“Family Guy” creator-exec producer Seth MacFarlane emceed in L.A. and opened with a parody on “Ya Got Trouble” from “The Music Man,” lamenting the growth of nonscripted TV with such lines as, “… with a capital T that rhymes with C that stands for crap” and, “Without a script, this town would fall off the fucking map.”

Larry David received among the biggest laughs of the night in accepting the Paddy Chayefsky lifetime achievement award for television, noting that something bad always happens to him after anything positive. “This has doom and gloom written all over it,” David said. “It’s a great honor, but not worth getting hit by a bus.”

“Curb Your Enthusiasm” trouper Susie Essman hosted in New York. She dubbed the WGA East an org with “half the power of the lollipop guild — without the lollipops or the midgets.”

At both events, there were multiple mentions made of the WGA’s strike in 2007-08, with Levitan and “Mad Men” chief Matthew Weiner citing their pride in the guild for standing up to the studios. WGA East prexy Michael Winship showed off the org’s new logo at the Gotham ceremony and added, “Coming soon to a picket sign near you!”

Full Winners List:

SCREEN WINNERS

ORIGINAL SCREENPLAY“The Hurt Locker” Written by Mark Boal; Summit Entertainment

ADAPTED SCREENPLAY“Up in the Air” Screenplay by Jason Reitman and Sheldon Turner; Based upon the novel by Walter Kirn; Paramount Pictures

LONG FORM – ORIGINAL – over one hour – one or two parts, one or two airing times “Georgia O’Keeffe”Written by Michael Cristofer; Lifetime

LONG FORM – ADAPTATION – over one hour – one or two parts, one or two airing times “Taking Chance”Teleplay by Lieutenant Colonel Michael R. Strobl, USMC (Ret.) and Ross Katz, Based on the short story by Lieutenant Colonel Michael R. Strobl, USMC (Ret.); HBO